JP2007232457A - Repairing method of penetration nozzle, and plug for nozzle port - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repairing method of a nozzle section that can be repaired from outside, and to provide a plug for a nozzle port used for the repairing method. <P>SOLUTION: The repairing method of a vessel section 1 is used when a welded part 1b between a nozzle port 1a provided in the vessel section 1 and a nozzle 2 inserted into the nozzle port 1a is present on the inner surface 1c in the vessel section 1. The repairing method comprises: a nozzle cutting/removing step for cutting the nozzle 2 between the inner surface 1c and the outer surface 1d of the vessel section 1 and removing the nozzle 2 projecting to the side of the cut outer surface 1d; a nozzle port plug insertion step for inserting a nozzle port plug 4 formed so that it blocks the nozzle port 1a after the removal from the side of the outer surface 1d; and a welding/junction step for welding and joining the vessel section 1 and the nozzle port plug 4 on the outer surface 1d. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for repairing a vessel portion having a nozzle, and a nozzle plug used therein, and more particularly to a method for repairing a nozzle of a nuclear reactor vessel.

  Among the nuclear reactors, it is known that light water reactors include boiling water light water reactors (BWR) and pressurized water light water reactors (PWR).

  A boiling water light water reactor (BWR) generates steam through a nuclear reactor vessel containing nuclear fuel as a heat source, and uses the steam for driving a steam turbine to generate electric power. At that time, since the steam to be used is made from water containing a radioactive substance, strict management is required even when passing through a steam turbine or a condenser.

  A pressurized water reactor (PWR) introduces primary system water into a steam generator as high-temperature and high-pressure water through a reactor vessel and a pressurizer, and generates steam from the secondary system water by heat exchange. It is used for driving to generate electricity. Structurally, water containing radioactive materials does not pass through the steam turbine or condenser, so that the maintainability of the power generation part such as the steam turbine is improved as compared to the boiling water light water reactor.

  In order to control the power of these reactors, it is necessary to control the reactivity by adjusting the number of neutrons in the reactor. Therefore, a control rod made of a control material that absorbs neutrons is inserted into the reactor in the stopped state, and control is performed so that neutrons associated with the fission reaction are absorbed and the critical state is not reached. Also, at the start of the reactor, the number of neutrons in the reactor is increased by gradually pulling out the control rod, and the reaction is increased until the rated output is achieved. In an emergency, all control rods are inserted and the reactor is stopped.

  Here, for example, a control rod driving device for driving the control rod is attached to a nozzle provided at the bottom of the reactor vessel in the case of a boiling water light water reactor, and at the top of the reactor vessel in the case of a pressurized water light water reactor. It has been. In addition, such a nozzle part (reactor vessel inlet / outlet tube, thermometer mounting tube, safety valve tube for pressurizer, steam generator inlet / outlet tube for steam generator) These are mainly made of stainless steel or Ni alloy. In addition, in order to keep the airtight and confine radioactive materials, the material of the nuclear vessel containing the nuclear fuel is made of a strong metal that can withstand high pressure, and is further lined with stainless steel.

  However, when placed in a corrosive environment (the situation where high-temperature high-pressure water of a reactor coolant that acts as a corrosive agent exists) in the presence of tensile stress, these stainless steels and Ni alloys have stress corrosion cracking (SCC) and primary Since cooling water stress corrosion cracking (PWSCC) occurs, there is a possibility of damage to the nozzle and the vicinity of the nozzle mounting portion. Therefore, it is necessary to repair the vicinity of the nozzle mount as necessary.

  Therefore, the nozzles fixedly supported by the lower mirror weld of the reactor vessel are cut at the upper and lower portions of the welds to remove the upper nozzle and the lower nozzle. Then, the defective part including the base material part of the nuclear reactor vessel or the potential defect-prone part is removed, and the base material removing part that becomes the strength member is built-up welded and restored to the original state. Then, rust prevention measures are taken in the lower mirror through hole of the reactor vessel, and then the lower nozzle is inserted into the lower mirror through hole from below and fixed to the nozzle by welding, and the lower nozzle is inserted. A technique of fixing the tip to the upper nozzle by welding is known. (See Patent Document 1)

  However, when repairing a reactor vessel as described above, it has been conventionally necessary to work inside the vessel with a high radiation dose. This is not preferable in order to reduce the radiation dose to which the worker is exposed.

Japanese Patent Laid-Open No. 2-102492

  Then, an object of this invention is to provide the repair method of the container part which can be easily repaired from the outer side of a container, and the nozzle plug used for it.

  In the following, means for solving the problem will be described using the numbers used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers are added to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers should not be used for the interpretation of the technical scope of the invention described in [Claims].

  In the repair method of the present invention, the welded portion (1b) between the nozzle hole (1a) provided in the container portion (1) and the nozzle (2) inserted into the nozzle hole (1a) It is a repair method of a container part (1) when existing in the inner surface (1c) of a part (1). In the repair method of the present invention, the nozzle (2) is cut between the inner surface (1c) and the outer surface (1d) of the container part (1), and the cut outer surface (1d) side A nozzle cutting / removing step for removing the nozzle (2) projecting to the nozzle, and a nozzle hole plug (4) formed so as to close the nozzle hole (1a) after the removal are provided on the outer surface (1d). And a nozzle hole plug insertion step of inserting from the side, and a welding joint step of welding the container portion (1) and the nozzle hole plug (4) at the outer surface (1d).

  By performing such a repairing method, the nozzle hole (1a) in which the internal fluid leaks due to breakage can be easily closed from the outside. Therefore, it is not necessary to work inside the container part (1) having a high radiation dose. Further, by eliminating the internal work, the number of repair processes can be greatly reduced and the work difficulty level can be reduced, so that necessary costs, time, and the like can be reduced.

  When the nozzle hole plug (4) is inserted into the nozzle hole (1a), the stopper inner surface (4a-1) positioned on the inner surface (1c) side and the outer surface (1d) side are positioned. A stopper main body (4a) having a stopper outer surface (4a-2) having a stopper edge (4a-3) along the hole edge (1a-1) of the nozzle hole (1a); And a protrusion (4b) formed on the stopper outer surface (4a-2).

  By inserting the nozzle hole plug (4) having the protrusion (4b) in this way into the nozzle hole (1a), the protrusion (4b) becomes a mark, and automatic welding is easy in the welding joining step. It becomes.

  In this case, it is preferable that at least the tip of the projection (4b) of the nozzle hole plug (4) has a rotationally symmetric shape with respect to a certain center line. For example, the upper surface of the protrusion (4b) is preferably circular, and the protrusion (4b) of the nozzle hole plug (4) is preferably conical.

  By making the shape of at least the tip of the projection (4b) of the nozzle plug (4) to be inserted into the nozzle hole (1a) rotationally symmetric with respect to a certain center line, the projection (4b) Circumferential welding with a constant peripheral speed at the center becomes easy. That is, it becomes easy to make constant the welding heat input that has a great influence on the properties of the weld metal such as strength and toughness.

  Furthermore, heat treatment after welding is required depending on the material of the welded part. However, in a reactor vessel or the like, the inside of the vessel cannot be installed, or a heater for heat treatment cannot be installed, or stainless steel is used as the material. For this reason, it is conceivable that the material deteriorates when heat treatment is performed. In such a case, in order to obtain a tempering effect by reheating the subsequent welding of the weld affected zone during the first layer welding, the welding torch used for welding is perpendicular to the plug outer surface (4a-2). More preferably, it is held and joined by a temper bead welding method around the apex or center point (4b-2) of the protrusion (4b).

  In the case of restoring the function of the nozzle, the repair method according to the present invention further includes a plug located on the outer surface (1d) side and along the hole edge (1a-1) of the nozzle hole (1a). A first hole machining step for forming a first hole (5) in a direction perpendicular to the plug outer surface (4a-2) having an edge (4a-3), and vertically upward with respect to the nozzle hole (1a) A second hole machining step for forming a second hole (6), a nozzle insertion step for inserting a new nozzle (7) into the second hole (5), the container (1) and the new tube It is preferable to have a new installation nozzle joining step for joining the table (7).

  By having such steps when repairing the reactor vessel, etc., the damaged nozzle can be easily recovered from the outside without any work inside the reactor vessel where the radiation dose is high. Can be made.

  In this case, the plug body (4a) has a plug hollow portion (4a-4) extending from the plug inner surface (4a-1) to the front of the plug outer surface (4a-2), and the plug hollow portion ( 4a-4) is preferably inserted into the nozzle hole plug (4) having a plug body (4a) having a hollow bottom surface (4a-5) parallel to the plug outer surface (4a-2). . According to such a process, since the plug hollow portion (4a-4) becomes apparent during the first hole processing, the second hole processing is performed by using the plug hollow portion (4a-4) as a reference. Positioning becomes easy.

  Moreover, by inserting the said nozzle hole plug (4) which comprises the plug main-body part (4a) whose said plug hollow part (4a-4) is the plug hollow part (4a-4) formed in the column shape. Thus, the processing position alignment of the second hole processing becomes easier.

The new nozzle connection step includes
A pair of columnar members having a shape obtained by cutting the columnar member in the longitudinal direction, the first columnar member (8d) and the second column having a width that decreases from the proximal end (8b) to the distal end (8a) in the longitudinal direction. Using the restraining jig (8) having a configuration in which the columnar member (8e) is brought into contact with the base end portion (8b) so as to be positioned on the other tip end portion (8a) side, the first columnar member (8e) is used. The nozzles (8d) and the second columnar member (8e) are arranged so that the short direction of the contact surface (8c) is perpendicular to the radial direction of the container part (1) formed in a columnar shape ( Inserting the internal remaining portion of 2) into the new nozzle (7) and aligning the internal residual portion with the new nozzle (7);
It is preferable to include a step of joining the container part (1) and the new nozzle (7) in a state where the internal remaining part and the new nozzle (7) are aligned.

  When the new nozzle (7) is joined to the container part (1), there is a concern that the new nozzle (7) may fall in the radial direction of the cylindrical container part (1). By using the shape restraining jig (8) in the above direction, the new nozzle (7) can be prevented from collapsing, and both the nozzles can be stretched and supported from the inner diameter side. It is possible to make the centers of the nozzle (2) and the newly installed nozzle (7) remaining inside the tube more accurately.

  The new nozzle (7) includes a first outer diameter portion (2a) having the same outer diameter as the nozzle (2) and a second outer diameter portion having an outer diameter smaller than that of the nozzle (1). It is preferable to include (2b) and a third outer diameter portion (2c) subjected to R processing between the first outer diameter portion (2a) and the second outer diameter portion (2b). By inserting the new nozzle (7) having such a structure, interference between the new nozzle (7) and the welding torch can be prevented when the new nozzle (7) is joined by welding.

  The nozzle plug (4) according to the present invention is a nozzle plug inserted into a nozzle hole (1a) provided so as to penetrate the container part (1). When the said nozzle hole plug (4) is inserted in the said nozzle hole (1a), the stopper inner surface (4a-1) located in the inner surface (1c) side of the said container part (1), and the said container part A plug outer surface (4a-2) having a plug edge (4a-3) along the hole edge (1a-1) of the nozzle hole (1a) located on the outer surface (1d) side of A stopper main body (4a) and a protrusion (4b) formed on the stopper outer surface (4a-2) are provided. The nozzle plug (4) having such a structure facilitates the work of welding the nozzle plug (4) to the container part (1) in order to close the nozzle hole (1a).

  By performing the repairing method of the present invention, the nozzle hole 1a in which the internal fluid leaks due to breakage can be easily closed from the outside. For this reason, it is not necessary to work inside a vessel portion having a high radiation dose, such as a reactor vessel. Further, by eliminating the internal work, the number of repair processes can be greatly reduced and the work difficulty level can be reduced, so that necessary costs, time, and the like can be reduced. In addition, the repaired nozzle can have the same structural strength and welding quality as the existing nozzle.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1A shows a cross section of a lower part of a nuclear reactor vessel 1 of a boiling water light water reactor and its periphery. FIG. 1B shows the vicinity of the junction between the reactor vessel 1 and the nozzle 2 in FIG. 1A.

  The boiling water type light water reactor includes a reactor vessel 1 as shown in FIGS. 1A and 1B, and the reactor vessel 1 is supported on a support pedestal 10 via a support skirt 11. A plurality of control rod drive mechanisms 20 are vertically suspended in the bottom of the reactor vessel 1 formed with a stainless steel layer 9 on the inner surface and mirror-finished. The nozzle 2 for the control rod drive mechanism 20 is a reactor vessel. 1 is inserted into a nozzle hole 1 a formed so as to have a groove provided at a lower portion of 1, welded at a welding portion 1 b, and fixed to the reactor vessel 1.

  Further, a neutron flux detector 30 appropriately disposed between a plurality of control rod drive mechanisms 20 measures and monitors a neutron flux generated in a core portion (not shown), and displays an output of the reactor and an evaluation of burnup. Do. The neutron flux detector 30 is guided to the outside by a neutron flux detector nozzle 3 welded and joined in the lower part of the reactor vessel 1 inside the vessel.

  The nozzle 2 for the control rod drive mechanism 20 and the nozzle 3 for the neutron flux detector are made of stainless steel or Ni-based alloy, and stress corrosion cracking or the like occurs at the welded portion 1b with the reactor vessel 1 depending on the environment. Damage can occur. If damage grows and becomes large, reactor water in the reactor vessel 1 may leak out of the reactor vessel 1. Therefore, this leak is constantly monitored by various detectors, and is also detected during periodic inspections. When a leak is detected, measures to prevent this leak are taken.

  Hereinafter, an example of the repair method according to the present invention when damage occurs to the welded portion 1b of the reactor vessel 1 and the nozzle 2 will be described with reference to FIGS. 1B and 2A to 2E. The neutron flux detector nozzle 3 can be repaired in the same manner.

  FIG. 1B is an enlarged view of one of the nozzle holes 1a in FIG. 1A. In repairing the nozzle 2, first, as shown in FIG. 2A, a nozzle cutting and removing process is performed.

  In the nozzle cutting and removing step, first, the nozzle 2 is cut at a cutting portion 2d located outside the inner surface 1c of the reactor vessel 1 and inside the outer surface 1d of the reactor vessel 1. And the part which protruded outside the reactor vessel 1 among the nozzles 2 after a cutting | disconnection is extracted and removed.

  After the nozzle severing and removing step, as shown in FIG. 2B, a nozzle pier hole plug inserting step and a welding joining step are performed. In the nozzle hole plug insertion process, the nozzle hole plug 4 is inserted into the nozzle hole 1a from the outside. In the welding and bonding process, the reactor vessel 1 and the nozzle hole plug 4 are joined by welding. The reactor vessel 1 and the nozzle hole plug 4 are joined together by a built-up portion 13 formed by welding.

  The nozzle hole plug 4 inserted here is preferably shaped as shown in FIG. 3 in order to allow the nozzle 2 that has leaked to be easily closed and restored from the outside of the reactor vessel 1. .

  Specifically, the nozzle hole plug 4 includes a plug body 4a and a protrusion 4b. The plug body 4a has a plug inner surface 4a-1 and a plug outer surface 4a-2. The plug inner surface 4a-1 is located on the inner surface 1c side of the reactor vessel 1 when the nozzle hole plug 4 is inserted into the nozzle hole 1a. The plug outer surface 4a-2 is located on the outer surface 1d side when the nozzle hole plug 4 is inserted into the nozzle hole 1a. The plug edge 4a-3 of the plug outer surface 4a-2 has a shape along the hole edge 1a-1 of the nozzle hole 1a. The plug body 4a is further formed with a plug hollow portion 4a-4 extending from the plug inner surface 4a-1 to the front of the plug outer surface 4a-2. The plug hollow portion 4a-4 is a cylindrical shape cut obliquely, and has a hollow portion bottom surface 4a-5 that is parallel to the plug outer surface 4a-2.

  The protrusion 4b is formed to protrude from the plug outer surface 4a-2 of the plug body 4a. The protrusion 4b has a rotationally symmetrical shape with respect to a certain center line (shown by a broken line in FIG. 3) at least at the tip. Such a shape is suitable for using the protrusion 4b as a mark for moving the welding torch circumferentially when the reactor vessel 1 and the nozzle plug 4 are welded. In the present embodiment, the protrusion 4b is formed so that the protrusion upper surface 4b-1 is circular. The protrusion 4b can also be formed in a conical shape.

  2B, when welding the reactor vessel 1 and the nozzle plug 4, the welding torch 12 is held in a direction substantially perpendicular to the plug outer surface 4 a-2 of the nozzle plug 4. And it is more desirable to join by the temper bead welding method centering on the center point 4b-2 of the protrusion upper surface 4b-1 (that is, centering on the center line of the protrusion 4b).

  Through the above steps, the nozzle hole 1a where the leak has occurred can be easily closed from the outside of the reactor vessel 1.

  Further, in order to restore the nozzle hole 1a closed by the above repair method and restore the function, the new nozzle 7 is inserted and joined to the reactor vessel 1 as shown in FIGS. 2C to 2E. The More specifically, first, as shown in FIG. 2C, the first hole machining step is performed. In the first hole processing step, the first hole 5 is formed in a direction perpendicular to the plug outer surface 4a-2 of the nozzle hole plug 4, and the plug hollow portion 4a-4 of the nozzle hole plug 4 is exposed.

  Subsequently, as shown in FIG. 2D, a second drilling step is performed. In the second hole processing step, the second hole 6 is formed vertically upward according to the stopper hollow portion 4a-4. The plug hollow portion 4 a-4 functions as a mark for forming the second hole 6.

  Subsequently, as shown in FIG. 2E, a nozzle insertion process and a new nozzle connection process are performed. In the nozzle insertion step, after the groove is formed in the built-up portion 13, the new nozzle 7 is inserted into the second hole 6. In the new nozzle connection step, the reactor vessel 1 and the new nozzle 7 are joined by welding the new nozzle 7 and the built-up portion 13.

  Since a large number of nozzles 2 are formed in the reactor vessel 1, the interference between the welding torch and the new nozzle 7 can be a problem in the new nozzle connection process. Considering the interference between the welding torch and the new nozzle 7 during the new nozzle connection process, the new nozzle 7 has the same outer diameter as the nozzle 2 as shown in FIG. It consists of a first outer diameter portion 2a, a second outer diameter portion 2b having a small outer diameter, and a third outer diameter portion 2c that is R-processed between the first outer diameter portion 2a and the second outer diameter portion 2b. It is more desirable to have a structure.

  Further, in order to more accurately match the center of the nozzle 2 remaining inside the reactor vessel 1 and the center of the newly installed nozzle 7, both nozzles are held by a restraining jig 8 as shown in FIG. It is desirable to weld and join after fixing. The restraining jig 8 includes a first columnar member 8d and a second columnar member 8e which are formed by cutting a cylindrical member at a certain angle with respect to the axis in the longitudinal direction. The first columnar member 8d and the second columnar member 8e have such a shape that the width decreases from the proximal end portion 8b in the longitudinal direction toward the distal end portion 8a. The first columnar member 8d and the second columnar member 8e are in contact with each other at the contact surface 8c so as to face each other so that one base end portion 8b is located on the other distal end portion 8a side. The diameter of the restraining jig 8 changes in the direction indicated by the arrow 15 by turning the jack bolt 14. The diameter of the restraining jig 8 is increased to the arrow 15 by turning the jack bolt 14 so that the remaining nozzle 2 and the newly installed nozzle 7 are stretched from the inside by the first columnar member 8d and the second columnar member 8e. Thus, the new nozzle 7 can be prevented from falling down.

  The collapse of the new nozzle 7 is an angle θ formed by the new nozzle 7 and the outer surface 1d of the reactor vessel 1 in the vertical section that cuts the new nozzle 7 and the reactor vessel 1 (which is an acute angle). It tends to occur in the direction in the vertical cross section that minimizes the angle. In order to prevent such collapse of the new nozzle 7, the direction in which the diameter of the restraining jig 8 increases is to minimize the angle θ formed by the new nozzle 7 and the outer surface 1 d of the reactor vessel 1. It is preferable that the orientation of the contact surface 8c of the first columnar member 8d and the second columnar member 8e is adjusted so that it is in a vertical cross section. Here, it should be noted that the “diameter” in the “direction in which the diameter of the restraining jig 8 increases” is defined as the direction in which the “diameter” changes the most when the jack bolt 14 is turned. By adjusting the direction of the contact surface 8c in such a direction, it is possible to more effectively prevent the newly installed nozzle 7 from falling in the inclined direction.

  In the embodiment described above, the control rod drive mechanism nozzle and the neutron flux detector nozzle in the reactor vessel of the boiling water light water reactor were mainly handled, but the present invention is applied to a pressurized water light water reactor having a similar nozzle. Can also be used. The present invention can be suitably applied not only to a reactor vessel but also to a pressurizer or a steam generator vessel.

The lower part structure of the reactor vessel in a boiling water type light water reactor is shown. The structure around the nozzle hole in FIG. 1A is shown. 1B shows the vicinity of a nozzle hole after a nozzle cutting and removing step is performed on the structure shown in FIG. 1B. 2B shows the vicinity of the nozzle hole after the nozzle hole plug insertion step and the welding joint step are performed on the structure shown in FIG. 2A. 2B shows the vicinity of the nozzle hole after the first hole machining step is performed on the structure shown in FIG. 2B. 2C shows the vicinity of the nozzle hole after the second hole machining step is performed on the structure shown in FIG. 2C. 2D shows the periphery of the nozzle hole after the nozzle insertion step and the new nozzle connection step are performed on the structure shown in FIG. 2D. The shape of a nozzle hole plug is shown. The shape of the new nozzle is shown. The situation where the nozzle and the new nozzle are fixed by the restraining jig is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reactor vessel 1a ... Pipe hole 1b ... Welding part 1c ... Inner surface 1d ... Outer surface 2 ... Pipe stage 2a ... First outer diameter part 2b ... Second outer diameter part 2c ... Third outer diameter part 2d ... Cutting Portion 3 for neutron flux detector 4 Portion plug 4a-1 Plug body 4a-1 Inner surface 4a-2 Outer surface 4a-3 Edge 4a-4 Plug hollow portion 4a-5 Hollow Part bottom surface 4b ... Projection part 4b-1 ... Projection top surface 4b-2 ... Center point 5 ... First hole 6 ... Second hole 7 ... New nozzle 8 ... Restraint jig 8a ... Tip part 8b ... Base end part 8c ... Contact surface 8d ... 1st columnar member 8e ... 2nd columnar member 9 ... Stainless steel layer 10 ... Support base 11 ... Support skirt 12 ... Welding torch 13 ... Filler material 14 ... Jack bolt 15 ... Arrow 20 ... Control rod drive mechanism 30 ... Neutron flux detector

Claims (17)

A method of repairing the container part when a joint part between a nozzle hole provided in the container part and a nozzle inserted into the nozzle hole exists on the inner surface of the container part,
A nozzle cutting and removing step of cutting the nozzle between the inner surface and the outer surface of the container portion, and removing the nozzle protruding to the cut outer surface side;
A nozzle hole plug insertion step for inserting a nozzle hole plug formed so as to close the nozzle hole after being removed from the outer surface side; and
A welding joining step of welding the container part and the nozzle plug on the outer surface;
A container part repair method. It is the repair method of the container part of Claim 1, Comprising:
The nozzle hole plug is
A plug body comprising a plug inner surface located on the inner surface side when inserted into the nozzle hole and a plug outer surface located on the outer surface side and having a plug edge portion along the hole edge of the nozzle hole. And
A protrusion formed on the outer surface of the stopper;
A container part repair method. It is the repair method of the container part of Claim 2, Comprising:
A method of repairing a container part, wherein at least a tip part of the projecting part of the nozzle hole plug has a rotationally symmetric shape with respect to a certain center line. The repair method according to claim 3,
The method of repairing a container part, wherein the top surface of the protrusion of the nozzle hole plug is circular. The repair method according to claim 3,
The method of repairing a container part, wherein the protrusion of the nozzle hole plug has a conical shape. It is the repair method of the container part of Claim 3, Comprising:
The method for repairing a container part, wherein the welding joining step includes a step of holding a welding torch to be used in a direction perpendicular to the outer surface of the stopper and joining the welding torch by a temper bead welding method around the center line of the protrusion. It is the repair method of the container part as described in any one of Claims 1-6,
Furthermore,
A first hole processing step for performing a first hole processing in a direction perpendicular to a plug outer surface located on the outer surface side and having a plug edge along the hole edge of the nozzle hole;
A second hole machining step for performing a second hole machining vertically upward with respect to the nozzle hole;
A nozzle insertion step for inserting a new nozzle into the second hole formed by the second hole machining step;
A new nozzle connection step for bonding the container part and the new nozzle;
A method for repairing a container part having It is the repair method of the container part of Claim 7, Comprising: The said plug main-body part has a stopper hollow part extended from the said stopper inner surface to the front of the said stopper outer surface,
The said stopper hollow part is provided with the hollow part bottom face parallel to the said stopper outer surface, The repair method of a container part. It is the repair method of the container part of Claim 7, Comprising:
A method of repairing a container part, wherein the stopper hollow part is formed in a cylindrical shape. It is the repair method of the container part as described in any one of Claims 7-9,
The new nozzle connection step includes
Aligning the inner remaining portion and the new nozzle by inserting a restraining jig into the inner remaining portion of the nozzle and the new nozzle;
A method of repairing a container part, comprising the step of joining the container part and the new nozzle in a state where the internal remaining part and the new nozzle are aligned. It is the repair method of the container part of Claim 10, Comprising:
The restraining jig is
Including a pair of first and second columnar members in a shape obtained by cutting the columnar members in the longitudinal direction;
Each of the first and second columnar members has such a shape that the width decreases as it goes from the proximal end portion in the longitudinal direction to the distal end portion,
The first and second columnar members are in contact with each other so that the base end portion is located on the other tip end side. It is the repair method of the container part as described in any one of Claims 7-11,
The new nozzle has a first outer diameter portion having the same outer diameter as the nozzle, a second outer diameter portion having an outer diameter smaller than the nozzle, the first outer diameter portion, and the second outer diameter portion. A method for repairing a container portion including a third outer diameter portion subjected to R processing between the outer diameter portion and the outer diameter portion. A nozzle hole plug inserted into a nozzle hole provided so as to penetrate the container part,
When inserted into the nozzle hole, the stopper has a stopper inner surface located on the inner surface side of the container part, and a stopper edge part located on the outer surface side of the container part and along the hole edge part of the nozzle hole. A plug body portion comprising an outer surface;
A protrusion formed on the outer surface of the stopper;
A nozzle plug with a nozzle. It is the repair method of the container part of Claim 13, Comprising:
The said nozzle has a shape symmetrical with respect to a certain center line. The repair method according to claim 13,
The said nozzle is a conical hole plug. A nozzle hole plug having a circular top surface of the protrusion. From Claim 10 is a nozzle hole plug according to any one of claims 16,
The said plug main-body part has the plug hollow part extended from the said plug inner surface to the near side of the said plug outer surface, and the said plug hollow part is provided with the hollow part bottom face parallel to the said plug outer surface.

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